Glass nem problem or just how it grows?

[WXB]

I have a SPS that has been doing great over the months. the bottom of it seems like the tissue is not there. I know the thing has been growing. the top has gotten bigger and bigger. when they grow do or can the bottoms seem like they are a bit neglected? OR I found a glass nem on the same rock. could it be stinging the SPS and upsetting the bottom? it has attached to the rock so I can not move it away from the glass nem. I can not add a shrimp to eat the nem due to my harliquin bassolet. This is my first go at SPS. I have just two in there have had the tank up for 8 months the coral in there for 4 months. just 3 corals and 1 fish with some crabs. any thoughts. I am working on pics right now.

[dzhuo]

There are lots of reason why SPS would lose their flesh. If you have a large colony with dense branches, light and flow will be hard to reach inside the coral which could cause tissue lost. This is very common even for an otherwise healthy acro. If you have SPS predator (such as AEFW), it's possible the flesh is being consumed. If you have a alk swing or water quality issue, it would cause RTN either from the tips, bottom up or anywhere else. Obviously, if you have a pest anemone physically in contact with the coral, it will most certainly cause tissue lost as well around the contact point. The possibility is endless and lots of times we simply don't know why which force us to physically remove the affected area hoping to save the rest.

Depends on the actual cause, the tissue lost might or might travel up the body. For example, if your coral is healthy and growing (like you mentioned) and the tissue lost is really caused by the anemone stinging it, the coral will recover once you remove the pest. If it's caused by other reasons such as light, flow or water quality issue, it's very likely the condition will continue to worse until you fix whatever problem it's there. If the anemone is your first suspicious, I would just remove it (you will have to before it spread anyway) and see if the coral recover. Is this the only SPS you have? Have other SPS show signs of tissue lost? Have you check the usual alk / cal / mag just to make sure they are stable? Have you dip the coral or inspect closely for pest?

[WXB]

Here are the pictures. as you can see the glass nem has moved from under it to in front of it. all my levels are good and I have not had a drop or increase in levels. good on water changes ect. I know how to keep the water but what i dont know is exactly how it grows. I know its getting larger but I do also see things changing. for the good or bad is my question. It has attached to the rock so I cant just move it without breaking it. Its in a prime spot for light.

This glass nem I try ripping them out but I cant. I got some red hary crabs to try to take care of the problem. If i put in a shrimp I know for a fact that my Bassolet is going to eat it. Any thoughts?

[dzhuo]

I am not sure what red hary crab you are talking about. Do you have a picture? I am personally not aware of any crab (reef safe) which are known to prey on aiptasia (which is what you have). Judging from the location of the anemone, I don't think the STN is caused by the aiptasia either. Recording from memory, it seems like you always start with wild or mari-culture SPS colonies? If so, these are known to be fairly problematic since it's hard to replicate exactly the condition they are known to grow. Have you try a small frag to see how it does? If the STN continue to move up, I would suggest you frag the colonies to stop the tissue lost.